The phrase "has been jointly" is correct and usable in written English.
It can be used to indicate that two or more people have collaborated in reaching a certain outcome. For example: "The decision to hire a new team member has been jointly decided by all members of the board."
Ha Noi, 26 November 2009 – To introduce and advocate for the adoption of a new approach to child poverty, a National Conference has been jointly organized in Ha Noi today by the Ministry of Labour, Invalids and Social Affairs MOLISAA), the Ministry of Planning and Investment (MPI), and the United Nations Children's Fund (UNICEF).
A press release to this effect has been jointly issued by Lee Jasper, Viv Ahmun and Stafford Scott.
If the president has been jointly chosen by the two blocs, the hope is that this might work.
(The new British office's £1m budget has been jointly underwritten by Cranfield and the South Australian government).
The Nobel peace prize has been jointly awarded to 17-year-old Malala Yousafzai and Indian child rights campaigner Kailash Satyarthi.
The case, in the high court's commercial division, has been jointly brought by the OFT and seven leading retail banks and the Nationwide building society.
Since then, the award has typically been given every year to one author, although in some years it has been jointly offered to two.
The pride of the Brazilian space effort is the Cbers satellite, which has been jointly developed with China in a $300 million program.
The website has been jointly developed by the Advertising Standards Authority (ASA), the Authority for Television On Demand, the BBC Trust, the British Board of Film Classification, Ofcom, the Press Complaints Commission (PCC) and the Video Standards Council.
The Climate Change Educational Resource Pack has been jointly funded by the Beacon for Wales, Countryside Council for Wales and the INTERREG IMCORE project (Innovative Management for Europe's Changing Coastal Resource) project.
Catherine Hagen Pepe, a retired lawyer with expertise in issues of workplace discrimination, has been jointly appointed by Morgan and the law firm Mehri & Skalet, which represented plaintiffs in the 2007 settlement.
